Hot and Mucky
Seal wet grass cuttings in a plastic bag.
For safety, seal this inside another bag.
Wrap the bags in some form of thermal insulation (e.g. blanket, plastic foam, etc.).
For comparison, set up a second set of bags, but with dry grass.
After a few days, compare the temperatures of the wet and dry grass. In one of the bags, the grass should have started to rot. The organisms causing this decay will have been releasing heat as they first digest the grass and then respire. This is an example of the use of biomass that is unsuitable for conventional burning (in contrast to wood, which is suitable).
Dispose of the sealed bags and their contents hygienically.
Suggest how this basic demonstration might be scaled up and modified so it could be used to pre-heat water going into a boiler system. What technical problems have to be overcome to make the idea work?
Energy Sources Activity Center
Energy Chest Home